摘要
：以天山乌鲁木齐河源１号冰川为例，系统地分析了冰川区降水的形成因素，阐述了冰川作为 特殊性质的下垫面对降水产生影响的机制，并定量化地计算出了乌鲁木齐河源１号冰川对降水的贡 献、冰川作为特殊性质下垫面对降水产生影响，其主要是通过致冷效应以及由此引发的温跃现象、逆 温现象、冰川风现象、凝结高度降低现象和水平降水现象的作用来实现的．乌鲁木齐河源１号冰川 作为特殊性质的下垫面对年降水的贡献比重随高度的不同而变化，从冰舌附近的１％向上逐渐增 大，在粒雪盆处达到最大，占冰面年降水量的７．５５％，再向上又有所减小．平均来说，冰川特殊下垫 面对降水的贡献相当于冰川上年降水总量的５．６０％
Generally speaking. precipitation on mountain glaciers is an intergrated result of weather system. terrain and specific property of the surface. The first two factors are dominant but the last one is quite important in some circumstances. In this paper, the Glacier No.1 at the headwaters of the Urumqi River, Tianshan Mountains. is selected to be a representative glacier and the factors producing precipitation on the glacial zone ale systematically analyzed. The effect of the glacier surface on precipitation is elaborated and the contribution rate of the Glacier No. 1 to the precipitation is calculated. The influence of glacier on precipitation due to its special surface is brought about through the cooling effect and its consequent phenomena: temperature jump, temperature reverse. glacier wind. coagulation height drop and horizontal precipitation. Owing to the special surface of snow and ice, the coagulation height above the Glacier No. 1 is about 146 m lower than that of Daxigou Meteorological Station about 1 000 m far away in July. The mean precipitation gradient of the Urumqi River basin (above 2 130 m) is 10. 11 mm / 100 m. different to the glacial zone, about 23 mm / 100 m. The contribution of the Glacier No.1 to precipitation is changing with height. At the tongue of the glacier only 1% of precipitation is contributed by glacier and the percentage increases gradually with height. At the firn basin (about 4 030 m) the contribution achieves the maximum. 7.55% of annual precipitation, and then decreases with height. The changing feature of air mass causes this phenomenon. When the air mass moves from the tongue of a glacier to the firn basin, its feature gradually changes and its mass loses through precipitation. When it arrives the firn basin its feature changes greatly and loses most of its mass. So when it moves up no more mass could lose and the contribution of glacier will decrease. In general, about 5.60% of the annual precipitation can be attributed to the glacier because of its special s
出处
《冰川冻土》
CSCD
北大核心
2000年第3期243-249,共7页
Journal of Glaciology and Geocryology
基金
中国科学院重大项目!(KZ951-A1-402-03)
中国科学院天山冰川观测试验站基金!(9905)资助项目
关键词
冰川
降水
冰川作用
定量分析
Glacier No. 1 at the Headwaters of the Urumqi River
precipitation
glacial effect
quantitative analysis
